The prior art is already aware of mulching types of rotary lawn mowers wherein the mower housing is essentially completely enclosed with a depending skirt portion to preclude the escape of the grass clippings and thus have the rotary cutter engage the clippings and to form them into small pieces which are ultimately deposited on the lawn and become mulch. As such, the clippings need not be discharged into a catcher or directly onto the lawn, but instead they are retained in the mower housing and are recut and processed into the mulch form and are then forced downwardly into the turf by the movement of the air created by the rotating grass cutter. Examples of prior art mowers with completely enclosed housings are found in U.S. Pat. Nos. 2,809,488 and 3,085,386 and in U.S. patent application Ser. No. 771,928 filed Feb. 25, 1977. In those examples, the mower housing is not provided with any lateral air or grass outlet opening, and the air is simply confined for constant turbulence and churning and can escape only downwardly from the mower housing itself.
Prior art examples of mowers having lateral discharges which are not completely open but which have housing portions extending across the discharge for intercepting debris or the like, or which have housing portions extending downwardly from the mower housing skirt itself while permitting some passage of air and grass therepast are found in U.S. Pat. Nos. 2,557,598 and 2,659,191 and 2,718,739 and 2,719,396 and 2,860,474. Of the aforementined, U.S. Pat. Nos. 2,659,191 and 2,718,739 are the most pertinent with regard to the present invention, but those two patents only show a perforated plate extending spaced from the tip of the rotary mower blade for the passage of air and clippings through the holes in the perforated plate. That is, the arrangement in those two patents is simply that of having a perforated plate which tends to impede the full flow of air from the mower housing but which still permits the grass clippings to go through the apertures or holes in the plate, much in the same manner that they would pass through an opening or regular discharge in a rotary mower housing. In addition to having the grass clippings pass through the apertures of the single plate shown in those two patents, the clippings or any debris or the like can be thrown or blown in a direct path through one of the openings, and thus the clippings or debris is widely scattered and there is some danger in a mower with that arrangement.
Accordingly, the present invention provides an improvement upon the mulching type of mowers, and it particularly provides an arrangement for a mulcher assembly which can be disposed over the outlet of a mower housing and thus confine the air and clippings and debris within the housing for the purpose of mulching same and then having it deposit downwardly below the housing itself, rather than have it below through the discharge opening or through any holes or the like in the mulcher assembly. Specifically, the present invention arranged the mulcher assembly with two spaced-apart plates which have apertures or holes in a staggered pattern between the two plates so that no grass or debris can move directly from the housing and past the plates and exteriorly of the mower, but all debris which is blown or thrown from the mower will be encountered by the mulcher plates, and only the air itself can fully escape beyond the mulcher plates. As such, the present invention provides an efficient and safe arrangement for a mulcher plate which can be attached to the mower housing and across the discharge opening thereof.
Still further, the present invention provides an arrangement for a rotary lawn mower wherein a mulcher assembly can be readily attached to or removed from the mower housing, and the assembly can be ready and easily provided by means of stamping and bending of the plates comprising the assembly, and the plates can be affixed together in an assembly wherein the two plates preclude the direct movement or escape of the debris from the mower housing, and thus a mulching action is achieved by the mower.
In accomplishing the aforementioned, the mulcher assembly of this invention provides a means for the escape of air from the mower housing, while precluding the escape of the grass or debris which is to be mulched, such as leaves or the like, and the escape of some of the air provides for a most efficient mulching action created by the air and debris remaining within the housing while the excess or at least some of the air created by the rotating cutter blade can escape and does escape through the mulcher assembly to insure the efficient action of the air and debris remaining in the housing.
Other objects and advantages will become apparent upon reading the following description in light of the accompanying drawings.